DALLAS, TX.- Heritage Auctions continues its legacy as the premier sports auction house offering a recently discovered Norman Rockwell original Saturday Evening Post cover study for the painting Tough Call in its August 19-20 Sports Platinum Night Auction. Historically significant New York Yankees memorabilia from Lou Gehrig, Mickey Mantle and Babe Ruth are also featured in the auction, now open for Internet-only bidding and concluding in Extended Bidding format on Saturday August 20.

The newly discovered Norman Rockwell study of "Tough Call" (est. $300,000+) was believed for decades to be just a framed print that was signed by Rockwell to umpire Beans Reardon. After presenting it to Heritage Auctions experts, the owners discovered it is actually an original oil on paper study work for one of Rockwell's most famous paintings.

"The Rockwell discovery is a wonderful story and we expect this work to do quite well considering the broad interest across sports, art and Rockwell enthusiasts," said Chris Ivy, director of Sports Auctions at Heritage. "Some of the greatest players in New York Yankees history in Gehrig, Mantle and Ruth are also represented in this auction with game-worn jerseys, game-used bats and trading cards. These are the elusive high-end items that serious collectors are constantly seeking."

Five lots from arguably the three greatest New York Yankees promise to capture collectors' attention and interest. Gehrig's 1937 Lou Gehrig Game Worn New York Yankees Jersey (est. $800,000+) and the 1924 Lou Gehrig Signed New York Yankees Rookie Contract (est. $500,000+) will be offered alongside the most valuable post WW-II trading card 1952 Topps Mickey Mantle #311 PSA NM-MT 8 (est. $500,000+) and Mantle's 1954 Mickey Mantle Game Worn New York Yankees Jersey, MEARS A9 (est. $400,000+).

An amazing offering from the Sultan of Swats' record-setting season of 54 home runs caps off the impressive of Yankees lots. Ruth's 1920 Babe Ruth Game Used Bat from the Louisville Slugger Traveling Exhibition, PSA/DNA GU 10 ($400,000+) offers collectors an unparalleled mix of historical context, high degree of game use, provenance and status as the genetic forebear of so much Ruth lumber to come.

Other top lots include but are not limited to:

· 1970 Ernie Banks Game Worn Chicago Cubs Jersey, MEARS A10 (est. $100,000+)

· 1915 Cracker Jack Baseball Cards Advertising Sign (est. $100,000+)

· 1961 Arnold Palmer British Open-Winning Driver with Palmer Letter (est. $80,000+)

· 2009 Stephen Curry NBA Summer League Opening Game Worn Golden State Warriors Jersey (est. $20,000+)

· 1982 Walter Payton 10,000 Yards Gained Presentational Game Football (est. $15,000+)